Plug-in hybrids
A plug-in hybrid uses a gasoline engine and an electric motor, but it gains the power to drive mainly from its electric motor and does not employ its conventional engine until its batteries get empty. The drained batteries can be recharged by using an external electric charger.
Conventional hybrids
Conventional hybrids also have a gasoline engine and an electric motor, as well as batteries. They use both their gasoline engine and electric motor to power the vehicle. But unlike plug-in hybrids, their batteries cannot be recharged by plugging into an external outlet. Their batteries can gain power through their wheels, brakes, and engine.
Electric cars
Electric cars only house an electric motor and batteries. Since they do not have an internal combustion engine, they rely entirely on their electric motor to roll the wheels. Because of the absence of the fossil fuel engine, they do not generate tailpipe emissions. Like plug-in hybrids, their batteries gain the power from an electric charger.